1. Win a Broadcaster or one of 3 Teles! The annual Supporting Member Giveaway is on. To enter Click Here. To see all the prizes and full details Click Here. To view the thread about the giveaway Click Here.

Tubes with different PC rating question help

Discussion in 'Glowing Bottle Tube Amp Forum' started by htloren, Mar 5, 2021.

  1. htloren

    htloren Tele-Meister

    Posts:
    349
    Joined:
    Nov 20, 2013
    Location:
    Manila
    Hi all,

    I have two TAD 6v6. One with a PC rating of 35, the other 32. A difference of 3. I seem to remember but can no longer find the reference, that a max PC difference of 3 is acceptable? Can I use them together? I understand my amp won’t be as clean but will it harm either the tubes or the amp? I am using a Deluxe Reverb.

    Thanks in advance!
     
  2. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    4,697
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Run em - it'll be just fine.
     
    htloren and hepular like this.
  3. htloren

    htloren Tele-Meister

    Posts:
    349
    Joined:
    Nov 20, 2013
    Location:
    Manila
    Thanks Corliss1!
     
  4. htloren

    htloren Tele-Meister

    Posts:
    349
    Joined:
    Nov 20, 2013
    Location:
    Manila
    • Hi all,

    One last question :)

    I had my Princeton Reverb next to my Deluxe Reverb. Speaker wise, the Princeton uses an Eminence GA10-SC64 10” and the Deluxe used it’s big brother, an Eminence GA-SC64 12”. Both pretty much the same tube sets except that the Princeton used TAD 6v6 GT-STR and the Deluxe used JJ 6v6. I wondered why they sounded different (since the speakers are “related”) and figured maybe the difference was in power tubes. I am using the Deluxe’s Normal channel for this comparison.

    I swapped out the JJ’s for TAD’s into my Deluxe. The differences I was hearing before are now gone. The Deluxe sounds the same now as my Princeton. A slight compensation on the Deluxe by adding .5 on the treble and less .5 on the bass maybe due to differences in cabinet and speaker size. This experiment wasn’t about making my Deluxe sound like a Princeton, just that the Princeton sounded better and so I wanted to improve the Deluxe.

    It seems with my Deluxe, the JJ’s are heavy on the bass and the TAD’s are heavy on the mids. I do prefer the TAD’s for both amps.

    Now, my question: using the TAD’s on the Deluxe, after checking the bias, the one tube (pc 35) showed 29mA and the one tube (pc32) showed 26mA. Both within TAD’s recommended 18-30mA.

    Sounds great to me but is the 3mA difference ok? Just making sure.

    Thanks!
     
    Last edited: Mar 5, 2021
  5. corliss1

    corliss1 Friend of Leo's Platinum Supporter

    Posts:
    4,697
    Joined:
    Sep 13, 2008
    Location:
    Lansing, MI
    Yup
     
    W.L.Weller and htloren like this.
  6. htloren

    htloren Tele-Meister

    Posts:
    349
    Joined:
    Nov 20, 2013
    Location:
    Manila
    Thanks again Corliss1 :)
     
  7. htloren

    htloren Tele-Meister

    Posts:
    349
    Joined:
    Nov 20, 2013
    Location:
    Manila
    Sorry, one last post...

    I am so happy!
     
    corliss1 likes this.
  8. Henry Mars

    Henry Mars Tele-Afflicted

    Posts:
    1,342
    Joined:
    Jan 17, 2014
    Location:
    Bucks Co. PA
    It's fine.
    These days with tubes I worry more about the P.I.A.(pain in the a$$) rating. Two of my amps are SS. The rest of them are all tube amps or hybrid. All in all most of the SS amps that I have heard these days sound as good or even better in some cases. I'm wondering if the tube aggravation is worth it anymore. Probably not.
    So pay close attention to the P.I.A. spec.
     
    htloren likes this.
  9. htloren

    htloren Tele-Meister

    Posts:
    349
    Joined:
    Nov 20, 2013
    Location:
    Manila
    Hi Henry Mars,

    A most excellent point. Definitely a lot of good options out there now. It’s also the reason why I had made the decision to stop at 4 amps. All tube. Maintenance.

    Loren
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.